The purpose of the study is to assess the safety and efficacy of targeted intramyocardial delivery of Auto-CD34+ cells for increasing exercise time and amelioration of anginal symptoms in subjects with refractory angina and chronic myocardial ischemia.

Participants without control of their angina symptoms in spite of maximal tolerated doses of anti-angina drugs. Participants must be on optimal therapy for their angina and must have been on a stable anti-anginal medication regimen for at least 4 weeks before signing the informed consent form.

Participants with obstructive coronary disease unsuitable for conventional revascularization due to unsuitable anatomy or comorbidity as determined at the site and confirmed by an independent adjudication committee.

Participants must have evidence of inducible myocardial ischemia.

Participants must experience angina episodes.

Participants must be able to complete 2 exercise tolerance tests on the treadmill within 3 weeks of randomization.

If female of childbearing potential, subject must not be pregnant and agree to employ adequate birth control measures for the duration of the study.

Main Exclusion Criteria:

Cardiovascular hospitalization within 60 days prior to potential study enrollment. Participant has had a successful or partially successful coronary artery bypass graft (CABG) within 6 months or PCTA within 60 days of potential study enrollment.

Participant has had a placement of a bi-ventricular pacemaker for cardiac resynchronization therapy (CRT) for heart failure within 180 days of potential study enrollment.

Participant has documented stroke or transient ischemic attacks (TIAs) within 60 days of potential study enrollment.

Participant has a history of moderate to severe aortic stenosis; or severe aortic insufficiency; or severe mitral stenosis; or severe mitral insufficiency.

Participant has a prosthetic aortic valve or a mechanical mitral valve replacement.

Participant has severe co-morbidity associated with a reduction in life expectancy to less than 3 years as a result of chronic medical illnesses.

Participants with cancer are excluded with the following exceptions:

Subjects with in-situ non-melanoma skin cancer or in-situ cervical cancer are not excluded.

Participants that have been cancer free for >= 5 years as determined by their oncologist are not excluded. Subjects with a prior history of stem cell transplant for cancer are excluded no matter how long they have been cancer-free.